I've witnessed a lot of old people double clicking on hyperlinks and buttons when a single click would suffice. This odd behavior would be troublesome for buttons that toggle a state. Take for example the following video playback button, which toggles between play and stop.

______ ______
| | | |
| |> | | [ ] |
|_____| |_____|

If an "old person" were to double-click this, the video would start playing and then immediately stop - making the the button appear broken. I could use some javascript to prevent double clicking - problem solved for "old people".

I've found that this javascript double-click prevention frustrates my "young users". Some young users want to revert their state immediately because they realized they made a mistake. This prevention forces them to wait 1 second or so. Clicking the button again within 1 second would do nothing, making it appear broken to the "young users".

2 Answers
2

I would suggest that you remove the Javascript double-click prevention feature and instead, display a message above the icon that says "Movie stopped." The message can fade away after a few seconds by itself, or immediately if they click on play again. This way, your power users aren't frustrated whereas your double-clickers will eventually get it.

Nice idea. However, the double-clicking may not be out of ignorance. Many "old" people, are not as apt at controlling a mouse as we may be. Double-clicking is then often reflexive and not something under conscious control. It may be hard for them not to double-click...
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Marjan VenemaMar 3 '11 at 7:58

Good point. In that case, it seems to me like this is something that should be handled at the OS level as part of the accessibility features, or perhaps by editing the mouse/trackpad preferences and setting the delay for interpreting "double click" to the maximum.
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HishamMar 3 '11 at 15:32

I like the idea of giving feedback on double click. The old geezers will pick up on the hint.
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JoJoMar 3 '11 at 21:08

At least with checkboxes, I prefer the "double-click is one click" method (does that make me old?) Also, for everything that opens an item and usually is used once - a navigation link, starting a program, etc.

Your case is a bit different: I migth go ahead just a tiny little snippet in the video, so quick-clicking is a reasonable use case. A similar case would be a button that opens a "new panel", and opening five panels is a common case.

I would't worry too much about "reversing a decision". Teach those young whippersnappers to think beforethey act. Back in my days.... -- seriously: that is a use case, but minor one.

Secret key you could toggle the behavior depending on e.g. "Shift" being pressed together with the click. That doesn't work in all circumstances, and does really help only expert users that stumble upon it. Not a real solution, but it's something you can answer when someone complains about the old-geezer-friendly behavior.

Feedback Give the user feedback about what happened. A messgae like Hisham suggests, or forcibly playing a frame or two. However, as Marjan Venema notes, the double-click might be from muscle memory, rather than intentional.

In my observasion of affected users, it's not a lack of skill, but them not making adistinction between "one-click thingies" and "two-click thingies". They one-click a desktop icon and wonder why nothing happens. Next, they double-click the quicklaunch icon. The effect is the same, though.